130 MADREPORARIA. 
septal granules are only here and there traceable, and never form a ring; the pali, on the other 
hand, form a conspicuous ring of eight small frosted points or plates. The columellar tubercle is 
small and deep down; the tangle is quite irregular. Down the sides of the branches the whole 
character of the skeleton changes ; the walls and septa are flat elegantly arranged flakes, with 
frosted edges and surface granules; near the top these granules show signs of forming the thin 
straggling wall-ridge. The pali gradually increase in size and the flakes get longer, but become 
less and less conspicuous. Interiorly the flakes spread in a network right across the calicle, 
just below the pali, to form a conspicuous columellar tangle. 
The section of the edge of the incrusting base shows a rather loose arrangement of smooth 
rounded trabecule joined by horizontal elements nearly as well developed as the trabecule. 
The section of one of the rounded tips shows only the earliest traces of trabecular development. 
The colour of the unbleached stock is a light fawn or brown. 
There are two complete stocks and a fragment; the smaller (a) probably shows the original 
stock, and rises 6-7 cm. high from an encrusting base, 4 cm. by 5 em. across, and with drooping 
edges. It is not the original cluster itself, for under the base traces of earlier explanate bases 
can be seen. The specimen is labelled “Thursday Island.” 0 is an old stock: the explanate 
base, with steeply sloping sides, has been left behind, the cluster above it rising into a mass 
12 cm. thick and 18 cm. in diameter. The coral is alive for a depth of about 6—7 cm., the 
lower half of the tangle consisting of dead coral. The dead branches round the stalk-like base 
radiate outwards almost horizontally (Pl. XX. fig. 1). 
This coral is not only interesting on account of its growth, but because of the two types of 
its calicles, the bulk of them being composed of flattened flakes. From the surface of the 
explanate base, which is composed of such calicles, small groups of calicles rise up and carry up 
the colony into vast tangles of branches, and on these upgrowths the calicles have elements 
which are thin and ragged. 
a. Small specimen from Thursday Island Zool. Devt. 92. 12. 1. 139 
(coll. W. Saville-Kent), \ Se a a ae 
b. Large old stock from “Torres Strait” 
(coll, A. C. Haddon). 
c. A fragment, showing traces of the original 
branching (A, C, Haddon), 
Zool. Dept. 97. 3. 9. 220 and 226. 
120. Porites Great Barrier Reef (4927. (P. Queenslandic septima et vicesima.) 
(CAE QD aise LB 12IL, Oca ives ily) 
[Torres Strait, coll. A. C. Haddon; British Museum.] 
Description.—The corallum is explanate, with thin encrusting edges, rarely free. The middle 
area of the colony may increase greatly in thickness, and even rise into points and into large 
excrescences, rounded or angular, with constricted necks, and sometimes up to 4 cm. in height. 
